Bearing apparatus and methods

ABSTRACT

An apparatus including a first housing defining an opening and a bearing housing disposed in the opening so that movement of at least a portion of the bearing housing within the first housing and along a first axis is permitted, the bearing housing defining first and second bearing surfaces, the first and second bearing surfaces being spaced apart along a second axis to prevent movement of the bearing housing within the first housing and along the second axis, the second axis being perpendicular to the first axis.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of the filing date of U.S.Application No. 61/639,445, filed Apr. 27, 2012, the entire disclosureof which is incorporated herein by reference.

TECHNICAL FIELD

The disclosure is directed to an apparatus including a bearing housingfixed in one direction and moveable in a second, perpendiculardirection, along with methods of using such bearing housings andapparatuses.

BACKGROUND OF THE DISCLOSURE

Top drive systems are used to rotate a drill string made up of tubularswithin a wellbore. Some top drives include a quill that providesvertical float between the top drive and the drill string, where thequill is usually threadedly connected to an upper end of a tubular ofthe drill string to transmit torque and rotary movement to the drillstring. Alternatively, it may be indirectly linked to the drill stringthrough a clamp, for example.

While drilling, drilling fluids or drilling mud are delivered to thedrill string through a washpipe system connected to the quill. From thetop drive and associated wash pipe, the fluids are transported andsupplied to the drill string through the quill. Sometimes additionaldrilling fluids such as cement, chemicals, epoxy resins, etc. are alsodelivered downhole via the same system.

The washpipe system often has multiple components. Due to imperfectionsthat come with the machining process, as well as wear on components oncein use, there can be a difference between two diameters on a singlecomponent. Effectively, the center lines of two diameters of onecomponent are not shared perfectly. Instead, there is a distance betweenthe two center lines. Stacking multiple components introduces additionalcenter lines that may not be shared, and the distance between centerlines can increase. If the objective is to guide this stacked set ofcomponents on a common center, the distance between center lines will beforced to zero, introducing forces into the components.

The present disclosure is directed to apparatuses and methods to addressthis problem of undesired forces in the components. Thus, the presentdisclosure provides a unique structural arrangement that supports abearing and/or bearing housing such that it absorbs the differencesbetween components' center lines, or radial runout, by allowing motionof the bearing and/or bearing housing in the radial direction whilepreventing movement in a longitudinal direction. Absorbing radial runoutreduces the forces introduced into the components.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale. In fact, the dimensions of the variousfeatures may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 is a schematic of an apparatus according to one or more aspectsof the present disclosure.

FIG. 2A is a sectional view of an apparatus according to one or moreaspects of the present disclosure;

FIG. 2B is an enlarged sectional view of a portion of the apparatusshown in FIG. 2A; and

FIG. 3 is a flow chart illustration of a method of operating theapparatus of FIG. 2A, according to one or more aspects of the presentdisclosure.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides manydifferent embodiments, or examples, for implementing different featuresof various embodiments. Specific examples of components and arrangementsare described below to simplify the present disclosure. These are, ofcourse, merely examples and are not intended to be limiting. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.Moreover, the formation of a first feature over or on a second featurein the description that follows may include embodiments in which thefirst and second features are formed in direct contact, and may alsoinclude embodiments in which additional features may be formedinterposing the first and second features, such that the first andsecond features may not be in direct contact.

The present disclosure is directed to apparatuses and methods having aunique structural arrangement that support a bearing and/or bearinghousing such that it absorbs radial runout by allowing motion of saidbearing and/or bearing housing in one direction, e.g., the radialdirection, while maintaining rigidity in a second, perpendiculardirection, e.g., axial rigidity (face parallelism).

Referring to FIG. 1, illustrated is a schematic view of an apparatus 100demonstrating one or more aspects of the present disclosure. Theapparatus 100 is or includes a land-based drilling rig. However, one ormore aspects of the present disclosure are applicable or readilyadaptable to any type of drilling rig, such as jack-up rigs,semisubmersibles, drill ships, coil tubing rigs, well service rigsadapted for drilling and/or re-entry operations, and casing drillingrigs, among others within the scope of the present disclosure.

The apparatus 100 includes a mast 105 supporting lifting gear above arig floor 110. The lifting gear includes a crown block 115 and atraveling block 120. The crown block 115 is coupled at or near the topof the mast 105, and the traveling block 120 hangs from the crown block115 by a drilling line 125. One end of the drilling line 125 extendsfrom the lifting gear to drawworks 130, which is configured to reel outand reel in the drilling line 125 to cause the traveling block 120 to belowered and raised relative to the rig floor 110. The other end of thedrilling line 125, known as a dead line anchor, is anchored to a fixedposition, possibly near the drawworks 130 or elsewhere on the rig.

A hook 135 is attached to the bottom of the traveling block 120. A topdrive 140 is suspended from the hook 135. A quill 145 extending from thetop drive 140 is attached to a saver sub 150, which is attached to adrill string 155 suspended within a wellbore 160. Alternatively, thequill 145 may be attached to the drill string 155 directly. It should beunderstood that other conventional techniques for arranging a rig do notrequire a drilling line, and these are included in the scope of thisdisclosure.

The drill string 155 includes interconnected sections of drill pipe 165,a bottom hole assembly (BHA) 170, and a drill bit 175. The bottom holeassembly 170 may include stabilizers, drill collars, and/ormeasurement-while-drilling (MWD) or wireline conveyed instruments, amongother components. The drill bit 175, which may also be referred toherein as a tool, is connected to the bottom of the BHA 170 or isotherwise attached to the drill string 155. One or more pumps 180 maydeliver drilling fluid to the drill string 155 through a hose or otherconduit 185, which may be fluidically and/or actually connected to thetop drive 140. This embodiment includes an apparatus 200 that may bereferred to as a floating bearing apparatus disposed between the topdrive 140 and the quill 145. The apparatus 200 is described more fullyfurther below.

Still referring to FIG. 1, the top drive 140 is used to impart rotarymotion to the drill string 155. However, aspects of the presentdisclosure are also applicable or readily adaptable to implementationsutilizing other drive systems, such as a power swivel, a rotary table, acoiled tubing unit, a downhole motor, and/or a conventional rotary rig,among others.

The apparatus 100 also includes a control system 190 configured tocontrol or assist in the control of one or more components of theapparatus 100. For example, the control system 190 may be configured totransmit operational control signals to the drawworks 130, the top drive140, the BHA 170 and/or the pump 180. The control system 190 may be astand-alone component installed near the mast 105 and/or othercomponents of the apparatus 100. In some embodiments, the control system190 is physically displaced at a location separate and apart from thedrilling rig.

The washpipe system depicted often has multiple components. Due toimperfections that come with the machining process, there can be adifference between two diameters on a single component, or runoutbetween two diameters on a single component. Effectively, the centerlines of two diameters of one component are not shared perfectly.Instead, there is a distance between the two center lines, which isoften referred to as the total indicated runout (TIR). The runoutbetween two diameters is twice the TIR. Stacking multiple componentsintroduces additional center lines that may not be shared, and thedistance between center lines can increase. This can lead to an increasein the TIR. If the objective is to guide this stacked set of componentson a common center, the distance between center lines will be forced tozero, introducing forces into the components. Such forces can, forexample, cause premature wear or even component failure.

FIGS. 2A and 2B show an exemplary embodiment of the apparatus 200referenced in FIG. 1 that allows for TIR, and therefore, reduces thecreation of forces, such as a bending moment, within components of theapparatus 200. The apparatus 200 connects to, or is driven by, the topdrive 140 (FIG. 1). For explanatory purposes, the apparatus 200 isdivided into sections. Accordingly, as referenced in FIG. 2A, theapparatus 200 includes a first stationary section 202 and a secondrotating and reciprocating section 204. The stationary section 202connects with a non-rotating portion of the top drive 140, for example,and the rotating and reciprocating section 204 connects to a tubular ofthe drill string 155 (FIG. 1) to make a part of a well casing.

The following description references FIGS. 2A and 2B. A fluid flowpassage 206 having a longitudinal axis 208 extends through both thestationary section 202 and the rotating and reciprocating section 204.An inlet 210 to the flow passage 206 is formed at the stationary section202, and provides fluid to the quill 145 connected to the rotating andreciprocating section 204. A bonnet or housing 216 is disposed over boththe stationary section 202 and the rotating and reciprocating section204. In this embodiment, the housing 216 is rigidly connected to thestationary section 202 and includes an intermediate support section 217extending radially inwardly. In the exemplary embodiment shown, theintermediate support section 217 supports at least a portion of thestationary section 202 and the rotating and reciprocating section 204.In one embodiment, an opening exists in the intermediate support section217, the opening having a longitudinal axis arranged in parallel or “atleast substantially” (e.g., within 10 degrees) parallel to alongitudinal axis of the stationary section 202 and/or the rotating andreciprocating section 204. In one embodiment, the opening is at leastsubstantially cylindrical in shape and defines a center and an insidediameter of the housing 216 that passes through the center. In oneembodiment, the axis 208 extends longitudinally through the center ofthe opening of the intermediate support section 217.

Referring to FIGS. 2A and 2B, the stationary section 202 includes anupper connection 218, a housing fixture 220 coupling the upperconnection 218 to the housing 216, and a first portion 224 a of arotational seal 224. The upper connection 218 is a rigid element forminga portion of the fluid flow passage 206. The housing fixture 220 alsoforms a portion of the fluid flow passage 206 and is coupled to a flange226 securing the housing 216 in place.

The rotating and reciprocating section 204 includes a second portion 224b of the rotational seal 224, a first rotating component 228, a turnlock adapter 230, a washpipe referred to herein as a conduit 232, and areciprocating assembly 234.

The second portion 224 b of the rotational seal 224 abuts the firstportion 224 a of the rotational seal 224, coupling the stationarysection 202 and the rotating and reciprocating section 204 in a sealedand rotatable matter. Accordingly, the first and second portions 224 a,224 b of the rotational seal 224 accommodate rotation while preventingfluid ingress and egress between the fluid flow passage 206 and theouter environment.

The first rotating component 228 is fixedly connected to, and may carrythe second portion 224 b of the rotational seal 224. It attaches to anextending flange portion 236 that extends over the intermediate supportsection 217 of the housing 216, preventing the first rotating component228 from passing through the housing 216. The first rotating component228 is coupled to the turn lock adapter 230. In some embodiments, theturn lock adapter 230 forms a portion of the fluid flow passage 206. Inone embodiment, the turn lock adapter 230 extends through the opening inthe intermediate support section 217.

To accommodate the rotating first rotating component 228 and the turnlock adapter 230 in the stationary housing 216, the apparatus 200includes a plurality of bearing assemblies or bearings 238 and 240. Theplurality of bearings 238 and 240 are disposed between a bearing housing242 and the turn lock adapter 230. In one embodiment, the bearings 238and 240 are radial bearings. In one embodiment, the bearings 238 and 240are continuous rings. In another embodiment, the bearings 238 and 240are independently selected, e.g., such that one is a set of radialbearings and the other is a continuous ring. In one embodiment, thebearings 238 and 240 have an outer surface corresponding to an outerdiameter and have an inner surface corresponding to an inner diameter.In one embodiment, the outer diameter of the bearing 238 is equal to or“at least substantially similar” (e.g., difference between diameterswithin +/−10% of smaller diameter) to the outer diameter of the bearing240. In one embodiment, the inner diameter of the bearing 238 is equalto or at least substantially similar to the inner diameter of thebearing 240. In one embodiment, the bearing 238 has an upper bearingsurface and a lower bearing surface, and a bearing height between itsupper bearing surface and its lower bearing surface measured in adirection along the axis 208. In one embodiment, the bearing 240 has anupper bearing surface and a lower bearing surface, and a bearing heightbetween its upper bearing surface and its lower bearing surface measuredin a direction along the axis 208. In one embodiment, the apparatus 200may have any number of bearings or bearing assemblies.

The bearing housing 242 is contained within the opening in theintermediate support section 217. The bearing housing 242 includes anannular sealing element, such as an O-ring 244, disposed between theoutside surface of the bearing housing 242 and an inside surface of theopening of the intermediate section 217. The O-ring 244 typicallyextends circumferentially around the bearing housing 242. In anexemplary embodiment, an annular groove is formed in the outside surfaceof the bearing housing 242, and the O-ring 244 extends within theannular groove. In an exemplary embodiment, respective annular groovesare formed in the outside surface of the bearing housing 242 and theinside surface of the opening, and the O-ring 244 and an annular sealingelement, such an as an O-ring 246 extend within the respective annulargrooves. In one embodiment, an inside diameter of the O-ring 244 is lessthan an outside diameter of the bearing housing 242.

In one embodiment, the outside diameter of the bearing housing 242 isless than a diameter of the inside surface of the opening of theintermediate support section 217, creating a housing clearance. That is,the difference between the diameter of the inside surface of the openingof the intermediate support section 217 and the outside diameter of thebearing housing 242 is equal to the housing clearance in thisembodiment. In one embodiment, the housing clearance is equal to therunout associated with components of the apparatus 200. In oneembodiment, the housing clearance is equal to the runout that isassociated with components of the apparatus 200 and that is to beallowed within the floating bearing system. In one embodiment, thehousing clearance equals to the runout associated with components of theapparatus 200 so that radial translation of the bearing housing 242absorbs the runout associated with components of the apparatus 200. Inone embodiment, the housing clearance is equal to the TIR associatedwith components of the apparatus 200. In one embodiment, the housingclearance is equal to the TIR that is associated with components of theapparatus 200 and that is to be allowed within the apparatus 200. In oneembodiment, the housing clearance equals to the TIR associated withcomponents of the apparatus 200 so that the radial translation of thebearing housing 242 absorbs the TIR associated with components of theapparatus 200. In one embodiment, the outside diameter of the bearinghousing 242 correlates to the expected runout or TIR within thecomponents. In one embodiment, the radial translation of the bearinghousing 242 is along a transverse axis 247 of the bearing housing 242.In one embodiment, the transverse axis 247 of the bearing housing 242 isperpendicular to the axis 208. In one embodiment, the transverse axis247 extends radially through the center of the opening of theintermediate support structure 217.

In one embodiment, the bearing housing 242 has an upper surface spacedalong the axis 208 and a lower surface spaced along the axis 208. In oneembodiment, a bearing housing height is the distance between the uppersurface of the bearing housing 242 and the lower surface of the bearinghousing 242 measured along the axis 208. In one embodiment, the bearinghousing height is greater than the bearing height of the bearing 238 orthe bearing height of the bearing 240 or both. In one embodiment, theupper surface of the bearing housing 242 extends above the upper bearingsurface of the bearing 238. In one embodiment, the lower surface of thebearing housing 242 extends below the lower bearing surface of thebearing 240. That is, an annular groove is formed in an inside surfaceof the bearing housing 242, and the bearings 238 and 240 extend withinthe annular groove. In this embodiment, the bearings 238, 240 may bearranged so as to not contact the upper or lower surface of the bearinghousing 242.

In one embodiment, the bearing housing 242 has a flat bearing 248located above the upper surface of the bearing housing 242 to maintainaxial alignment of the bearing housing 242 with the axis 247. In oneembodiment, the bearing housing 242 has a flat bearing 250 located belowthe lower surface of the bearing housing 242 to maintain axial alignmentof the bearing housing 242 with the axis 247. In one embodiment, aloading nut applies pressure to the flat bearings 248 and 250 so thatthe bearing housing 242 does not rotate about the axis 208 whiletranslating in the radial direction along the transverse axis 247. Inone embodiment, any type of fastener may be used to apply pressure tothe flat bearings 248 and 250. In one embodiment, the flat bearings 248and 250 engage the bearing housing 242 to prevent movement of thebearing housing 242 along the axis 208. In one embodiment, the flatbearings 248 and 250 are radial and have an inner diameter and an outerdiameter. In one embodiment, the inner diameter of the flat bearings 248and 250 is equal to or greater than the outer diameter of the bearings238 and 240. In one embodiment, the flat bearings 248 and 250 do notcontact the bearings 238 and 240 so that at least a portion of thebearings 238 and 240 are free to rotate about the axis 208. In oneembodiment, the outer diameter of the flat bearings 248 and 250 areequal to or substantially similar to the outer diameter of the bearinghousing 242. In one embodiment, the flat bearings 248 and 250 areGarlock DU bearings. In another embodiment, the bearing housing 242 ismanufactured from a commercially available bearing material, such as SAE630.

In one embodiment, the turn lock adapter 230 is fixedly engaged with thewashpipe or conduit 232. In one embodiment, the conduit 232 is a pistonof a top drive 140. Accordingly, the conduit 232 rotates with the turnlock adapter 230. The conduit 232 is configured to form a portion of thefluid flow passage 206. In this example, the conduit 232 includes a body252 that extends through the opening of the intermediate section 217toward the quill 145. In one embodiment, a lower end 254 of the conduit232 has an outer diameter matching that of the body 252 of the conduit.In this embodiment, a sleeve 256 is configured to receive the lower end254 of the conduit 232. Accordingly, a diameter of an opening of thesleeve 256 is greater than the outer diameter of the lower end 254. Inone embodiment, the quill 145 includes an inner fluid flow passage andis configured to receive a lower end of the sleeve 256. Accordingly, thediameter of the inner fluid flow passage of the quill 145 is greaterthan an outer diameter of the lower end of the sleeve 256. In oneembodiment, the summation of runout associated with the quill 145, thesleeve 256, the conduit 232, or any combination thereof, results in alongitudinal axis of the turn lock adapter 230 being offset from theaxis 208 by a cumulative TIR. Instead of forcing a longitudinal axis ofthe turn lock adapter 230 to rotate about the axis 208, the turn lockadapter 230 may rotate about its longitudinal axis because of thehousing clearance.

In an exemplary embodiment, as illustrated in FIG. 3 with continuingreference to FIGS. 1-2B, a method of reducing bending moment withinstacked components, by operating the apparatus 200, is generallyreferred to by the reference numeral 300.

In an exemplary embodiment, at step 305, the bearing housing 242 isdisposed in the opening of the intermediate support structure 217.

In an exemplary embodiment, at step 310, movement of the bearing housing242 along the axis 247 is permitted in a first direction. Movement ispermitted along the axis 247 due to the difference between the diameterof the inside surface of the opening of the intermediate support section217 and the outside diameter of the bearing housing 242. In an exemplaryembodiment, this difference, or the housing clearance, correlates to theamount of TIR or runout that will be absorbed by the apparatus 200.Thus, movement in the first direction is permitted to absorb the runout.In one embodiment, the outside diameter of the bearing housing 242 isbased on the expected runout of the components. That is, as the expectedrunout increases, the outside diameter of the bearing housing 242decreases. In one embodiment, the movement in the first direction isequal to or lesser than the runout.

In an exemplary embodiment, at step 315, movement of the bearing housing242 along the axis 208 is prevented. In one embodiment, movement isprevented along the axis 208 due to the flat bearing 248 engaging theupper surface of the bearing housing 242 and the flat bearing 250engaging the lower surface of the bearing housing 242. Pressure can beapplied, using the flat bearings 248 and 250, in a direction along theaxis 208 to secure the bearing housing 242 at a location along the axis208.

In an exemplary embodiment, at step 320, the bearing housing 242 isurged to move in a second direction along the axis 247, where the seconddirection is opposite the first direction. In one embodiment, theannular sealing element, such as the O-ring 244, urges the bearinghousing 242 to move in the second direction along the axis 247. In oneembodiment, compression characteristics of the O-ring 244 correlate tothe urging of the bearing housing 242 along the axis 247. In oneembodiment, a thickness of the O-ring 244 correlates to the urging ofthe bearing housing 242 along the axis 247. In one embodiment, theO-ring 244 can be compressed by the TIR. In one embodiment, a hardnessof the annular sealing elements correlates to the urging of the bearinghousing 242 along the axis 247 and/or to vibration dampening within theapparatus 200. In one embodiment, the material of the annular sealingelements correlates to the urging of the bearing housing 242 along theaxis 247 and/or to vibration dampening within the apparatus 200. In oneembodiment, a cross-sectional shape of the annular sealing elementcorrelates to the urging of the bearing housing 242 along the axis 247and/or the vibration dampening within the apparatus 200. For example, aQuad-Seal, H-Seal, or any other variety of seal can correlate tovibration dampening characteristics within the apparatus 200. In oneembodiment, the annular sealing element may be a spring-energized lipseal or O-ring loaded lip seal, such as a Parker PolyPak® Seal. In oneembodiment, one or more annular grooves in the outside surface of thebearing housing 242 is not associated with an annular sealing element.For example, four annular grooves may be located on the outside surfaceof the bearing housing 242, but only two of the four annular grooves mayhave an annular sealing element located therein. In one embodiment, theapparatus 200 includes any number of annular grooves and any number ofannular sealing elements. In one embodiment, the number of annularsealing elements correlates to the urging of the bearing housing 242along the axis 247 and/or to vibration dampening within the apparatus200. Before or after operation of the apparatus 200, the number ofannular sealing elements may be altered to reduce or alter vibrationswithin the apparatus 200 while the apparatus is in operation.Additionally, before or after operation of the apparatus 200, an annularsealing element may be exchanged for an annular sealing element having adifferent hardness, thickness, shape, etc., or a combination thereof, toreduce or alter vibrations within the apparatus 200 while the apparatusis in operation. The annular sealing element characteristics, incombination with the number and placement of such annular sealingelements, can be adjusted to minimize or prevent undesirable levels ofvibration during operation of the apparatus 200. In one embodiment,reducing or altering vibrations within the apparatus 200 while theapparatus 200 is in operation inhibits or prevents the apparatus 200from resonating, or vibrating, at a frequency at which resonance of theapparatus 200, or a portion of the apparatus 200, occurs.

In an exemplary embodiment, at step 325, the bearing housing 242rotatably supports a first tubular member. In one embodiment, the firsttubular member is the turn lock adapter 230.

In an exemplary embodiment, at step 330, a second tubular member isspaced from the first tubular member along the axis 208. In an exemplaryembodiment, the second tubular member is the quill 145.

In an exemplary embodiment, at step 335, a third tubular member iscoupled to at least one of the first and second tubular members so thatthe third tubular member extends between the first and the secondtubular member. In one embodiment, the third tubular member is thesleeve 256. In one embodiment, the movement of the bearing housing 242and/or bearings 238 and 240 reduces any bending movement experienced bythe third tubular member or the sleeve 256.

In an exemplary embodiment, at step 340, a fourth tubular member iscoupled to at least one of the first and third tubular members so thatthe fourth tubular member extends between the first and the thirdtubular member. In one embodiment, the fourth tubular member is theconduit 232. In one embodiment, the movement of the bearing housing 242and/or bearings 238 and 240 reduces any bending movement experienced bythe fourth tubular member or the conduit 232.

In one embodiment, the radial translation or movement of the bearings238 and 240 and/or bearing housing 242 of the apparatus 200 in themethod 300 reduces a bending moment occurring within the conduit 232 orthe sleeve 256 or both.

The disclosure encompasses an apparatus, which has a first housingdefining an opening; and a bearing housing disposed in the opening sothat movement of at least a portion of the bearing housing within thefirst housing and along a first axis is permitted, the bearing housingdefining first and second bearing surfaces, the first and second bearingsurfaces being spaced apart along a second axis to prevent movement ofthe bearing housing within the first housing and along the second axis,the second axis being perpendicular to the first axis. In some aspects,the bearing housing is at least substantially annular in shape anddefines an outside diameter; wherein the opening is at leastsubstantially cylindrical in shape, and defines a center and an insidediameter of the first housing that passes through the center, the insidediameter of the first housing being greater than the outside diameter ofthe bearing housing; wherein the first axis extends radially through thecenter; and wherein the second axis extends longitudinally through thecenter. In some aspects, the difference between the outside diameter andthe inside diameter limits the range of movement of the bearing housingwithin the first housing and along the first axis. In some aspects, theapparatus further has a compressible element disposed in the opening andbetween an outside surface of the bearing housing and an inside surfaceof the first housing that is defined by the opening. In some aspects,the compressible element is coupled to the bearing housing andcompresses in response to movement of the bearing housing within thefirst housing and along the first axis. In some aspects, the apparatusfurther has a first flat bearing and a second flat bearing defining athird bearing surface and a fourth bearing surface, respectively;wherein the first and the second flat bearings are spaced along thesecond axis; and wherein the third and the fourth bearing surfacesengage the first and the second bearing surfaces, respectively, toprevent movement of the bearing housing within the first housing andalong the second axis. In some aspects, the apparatus further has: afirst tubular member around which the bearing housing circumferentiallyextends; a second tubular member spaced from the first tubular memberalong the second axis; and a third tubular member coupled to at leastone of the first and the second tubular members and extending betweenthe first and the second tubular members; wherein movement of thebearing housing within the first housing and along the first axisreduces any bending moment experienced by the third tubular member. Insome aspects, the third tubular member is coupled to the second tubularmember; wherein the apparatus further includes a fourth tubular membercoupled to the first tubular member and extending between the first andthe third tubular member, the fourth tubular member including anopposing first and a second end portion; and wherein movement of thebearing housing within the first housing and along the first axisreduces any bending moment experienced by the fourth tubular member. Insome aspects, the first, second, and third tubular members define afirst, a second, and a third internal passage, respectively; wherein thefirst end portion of the fourth tubular member extends within the firstinternal passage and at least the second end portion of the fourthtubular member extends within the third internal passage; and wherein atleast a portion of the third tubular member extends within the secondinternal passage. In some aspects, the apparatus further has: a topdrive; and a quill operably coupled to the top drive; wherein the secondtubular member is part of the quill, the third tubular member is asleeve of the top drive, and the fourth tubular member is a piston ofthe top drive. In some aspects, the apparatus further has a radialbearing disposed in the bearing housing, the radial bearing including; afirst ring to engage a tubular member; and a second ring engaged withthe bearing housing, the second ring extending circumferentially about,and spaced along the first axis from, the first ring. In some aspects,the apparatus further has a radial bearing disposed in the bearinghousing, the radial bearing including: a first ring to engage a tubularmember; and a second ring engaged with the bearing housing, the secondring extending circumferentially about, and spaced along the first axisfrom, the first ring; wherein the first flat bearing and the second flatbearing are generally annular in shape and define an inside diameter;and wherein the inside diameter of the first flat bearing and the secondflat bearing is greater than or equals to a diameter of the second ring.In some aspects, the radial bearing is disposed in the bearing housingbetween the first bearing surface and the second bearing surface.

The present disclosure also introduces a method including: disposing abearing housing in an opening defined by a first housing; permittingmovement of the bearing housing within the first housing and along afirst axis; and preventing movement of the bearing housing within thefirst housing and along a second axis, the second axis beingperpendicular to the first axis. In some aspects, the bearing housing isgenerally annular in shape and defines an outside diameter; wherein theopening is generally cylindrical in shape, and defines a center and aninside diameter of the first housing that passes through the center, theinside diameter of the first housing being greater than the outsidediameter of the bearing housing; wherein the first axis extends radiallythrough the center; and wherein the second axis extends longitudinallythrough the center. In some aspects, the difference between the outsidediameter and the inside diameter limits the range of movement of thebearing housing within the first housing and along the first axis. Insome aspects, the bearing housing moves in a first direction along thefirst axis; and wherein the method further includes urging the bearinghousing to move in a second opposite direction along the first axis inresponse to the movement of the bearing housing in the first directionalong the first axis. In some aspects, preventing movement of thebearing housing within the first housing and along the second axisincludes engaging a first flat bearing and a second flat bearing againstthe bearing housing, the first flat bearing and the second flat bearingbeing spaced along the second axis. In some aspects, the method furtherincludes: employing the bearing housing to rotatably support the firsttubular member; spacing a second tubular member from the first tubularmember along the second axis; and coupling a third tubular member to atleast one of the first and second tubular members so that the thirdtubular member extends between the first and second tubular members;wherein movement of the bearing housing within the first housing andalong the first axis reduces any bending moment experienced by the thirdtubular member. In some aspects, the method further includes coupling afourth tubular member to at least one of the first and third tubularmembers so that the fourth tubular member extends between the first andthird tubular members; wherein movement of the bearing housing withinthe first housing and along the first axis reduces any bending momentexperienced by the fourth tubular member. In some aspects, the first,second, and third tubular members define first, second and thirdinternal passages, respectively; wherein the first end portion of thefourth tubular member extends within the first internal passage and atleast the second end portion of the fourth tubular member extends withinthe third internal passage; and wherein at least a portion of the thirdtubular member extends within the second internal passage. In someaspects, the second tubular member is part of a quill operably coupledto a top drive, the third tubular member is a sleeve of the top drive,and the fourth tubular member is a piston of the top drive. In someaspects, employing the bearing housing to rotatably support the firsttubular member includes disposing a radial bearing coupled to the firsttubular member in the bearing housing, the radial bearing including: afirst ring to engage the first tubular member; and a second ring engagedwith the bearing housing, the second ring extending circumferentiallyabout, and spaced along the first axis from, the first ring; wherein thefirst flat bearing and the second flat bearing are generally annular inshape and define an inside diameter; and wherein the inside diameter ofthe first flat bearing and the second flat bearing is greater than orequals to a diameter of the second ring.

The present disclosure also introduces a method that includes: spacingapart first and second tubular members; coupling a third tubular memberto each of the first and second tubular members so that the thirdtubular member extends therebetween; rotatably supporting each of thefirst and second tubular members; and reducing any bending momentexperienced by the third tubular member while rotatably supporting eachof the first and second tubular members. In some aspects, the first,second, and third tubular members extend longitudinally along a firstaxis; wherein rotatably supporting each of the first and second tubularmembers includes: disposing a bearing housing in an opening defined by afirst housing; and extending the first tubular member within the openingso that the bearing housing circumferentially extends around the firsttubular member; and wherein reducing any bending moment experienced bythe third tubular member during rotatably supporting each of the firstand second tubular members includes: permitting movement of the bearinghousing within the first housing and along a second axis that isperpendicular to the first axis; and preventing movement of the bearinghousing within the first housing and along the first axis. In someaspects, the bearing housing moves in a first direction along the secondaxis; and wherein the method further includes urging the bearing housingto move in a second direction along the second axis in response to themovement of the bearing housing in the first direction along the secondaxis, the second direction being opposite to the first direction. Insome aspects, the second tubular member is part of a quill operablycoupled to a top drive, and the third tubular member is one of a sleeveand a piston associated with the top drive.

The foregoing outlines features of several embodiments so that a personof ordinary skill in the art may better understand the aspects of thepresent disclosure. Such features may be replaced by any one of numerousequivalent alternatives, only some of which are disclosed herein. One ofordinary skill in the art should appreciate that they may readily usethe present disclosure as a basis for designing or modifying otherprocesses and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein. Oneof ordinary skill in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions andalterations herein without departing from the spirit and scope of thepresent disclosure.

The Abstract at the end of this disclosure is provided to comply with 37C.F.R. §1.72(b) to allow the reader to quickly ascertain the nature ofthe technical disclosure. It is submitted with the understanding that itwill not be used to interpret or limit the scope or meaning of theclaims.

Moreover, it is the express intention of the applicant not to invoke 35U.S.C. §112(f) for any limitations of any of the claims herein, exceptfor those in which the claim expressly uses the word “means” togetherwith an associated function.

What is claimed is:
 1. An apparatus, comprising: a first housingdefining an opening; and a bearing housing disposed in the opening sothat movement of at least a portion of the bearing housing within thefirst housing and along a first axis is permitted, the bearing housingdefining first and second bearing surfaces, the first and second bearingsurfaces being spaced apart along a second axis to prevent movement ofthe bearing housing within the first housing and along the second axis,the second axis being perpendicular to the first axis.
 2. The apparatusof claim 1, wherein the bearing housing is at least substantiallyannular in shape and defines an outside diameter; wherein the opening isat least substantially cylindrical in shape, and defines a center and aninside diameter of the first housing that passes through the center, theinside diameter of the first housing being greater than the outsidediameter of the bearing housing; wherein the first axis extends radiallythrough the center; and wherein the second axis extends longitudinallythrough the center.
 3. The apparatus of claim 2, wherein the differencebetween the outside diameter and the inside diameter limits the range ofmovement of the bearing housing within the first housing and along thefirst axis.
 4. The apparatus of claim 1, further comprising acompressible element disposed in the opening and between an outsidesurface of the bearing housing and an inside surface of the firsthousing that is defined by the opening.
 5. The apparatus of claim 4,wherein the compressible element is coupled to the bearing housing andcompresses in response to movement of the bearing housing within thefirst housing and along the first axis.
 6. The apparatus of claim 1,further comprising a first flat bearing and a second flat bearingdefining a third bearing surface and a fourth bearing surface,respectively; wherein the first and the second flat bearings are spacedalong the second axis; and wherein the third and the fourth bearingsurfaces engage the first and the second bearing surfaces, respectively,to prevent movement of the bearing housing within the first housing andalong the second axis.
 7. The apparatus of claim 1, further comprising:a first tubular member around which the bearing housingcircumferentially extends; a second tubular member spaced from the firsttubular member along the second axis; and a third tubular member coupledto at least one of the first and the second tubular members andextending between the first and the second tubular members; whereinmovement of the bearing housing within the first housing and along thefirst axis reduces any bending moment experienced by the third tubularmember.
 8. The apparatus of claim 7, wherein the third tubular member iscoupled to the second tubular member; wherein the apparatus furthercomprises a fourth tubular member coupled to the first tubular memberand extending between the first and the third tubular member, the fourthtubular member comprising an opposing first and a second end portion;and wherein movement of the bearing housing within the first housing andalong the first axis reduces any bending moment experienced by thefourth tubular member.
 9. The apparatus of claim 8, wherein the first,second, and third tubular members define a first, a second, and a thirdinternal passage, respectively; wherein the first end portion of thefourth tubular member extends within the first internal passage and atleast the second end portion of the fourth tubular member extends withinthe third internal passage; and wherein at least a portion of the thirdtubular member extends within the second internal passage.
 10. Theapparatus of claim 9, further comprising: a top drive; and a quilloperably coupled to the top drive; wherein the second tubular member ispart of the quill, the third tubular member is a sleeve of the topdrive, and the fourth tubular member is a piston of the top drive. 11.The apparatus of claim 1, further comprising a radial bearing disposedin the bearing housing, the radial bearing comprising: a first ring toengage a tubular member; and a second ring engaged with the bearinghousing, the second ring extending circumferentially about, and spacedalong the first axis from, the first ring.
 12. The apparatus of claim 6,further comprising a radial bearing disposed in the bearing housing, theradial bearing comprising: a first ring to engage a tubular member; anda second ring engaged with the bearing housing, the second ringextending circumferentially about, and spaced along the first axis from,the first ring; wherein the first flat bearing and the second flatbearing are generally annular in shape and define an inside diameter;and wherein the inside diameter of the first flat bearing and the secondflat bearing are greater than or equals to a diameter of the secondring.
 13. The apparatus of claim 12, wherein the radial bearing isdisposed in the bearing housing between the first bearing surface andthe second bearing surface.
 14. A method, comprising: disposing abearing housing in an opening defined by a first housing; permittingmovement of the bearing housing within the first housing and along afirst axis; and preventing movement of the bearing housing within thefirst housing and along a second axis, the second axis beingperpendicular to the first axis.
 15. The method of claim 14, wherein thebearing housing is generally annular in shape and defines an outsidediameter; wherein the opening is generally cylindrical in shape, anddefines a center and an inside diameter of the first housing that passesthrough the center, the inside diameter of the first housing beinggreater than the outside diameter of the bearing housing; wherein thefirst axis extends radially through the center; and wherein the secondaxis extends longitudinally through the center.
 16. The method of claim15, wherein the difference between the outside diameter and the insidediameter limits the range of movement of the bearing housing within thefirst housing and along the first axis.
 17. The method of claim 14,wherein the bearing housing moves in a first direction along the firstaxis; and wherein the method further comprises urging the bearinghousing to move in a second opposite direction along the first axis inresponse to the movement of the bearing housing in the first directionalong the first axis.
 18. The method of claim 14, wherein preventingmovement of the bearing housing within the first housing and along thesecond axis comprises engaging a first flat bearing and a second flatbearing against the bearing housing, the first flat bearing and thesecond flat bearing being spaced along the second axis.
 19. The methodof claim 14, further comprising: employing the bearing housing torotatably support the first tubular member; spacing a second tubularmember from the first tubular member along the second axis; and couplinga third tubular member to at least one of the first and second tubularmembers so that the third tubular member extends between the first andsecond tubular members; wherein movement of the bearing housing withinthe first housing and along the first axis reduces any bending momentexperienced by the third tubular member.
 20. The method of claim 19,further comprising coupling a fourth tubular member to at least one ofthe first and third tubular members so that the fourth tubular memberextends between the first and third tubular members; wherein movement ofthe bearing housing within the first housing and along the first axisreduces any bending moment experienced by the fourth tubular member. 21.The method of claim 20, wherein the first, second, and third tubularmembers define first, second and third internal passages, respectively;wherein the first end portion of the fourth tubular member extendswithin the first internal passage and at least the second end portion ofthe fourth tubular member extends within the third internal passage; andwherein at least a portion of the third tubular member extends withinthe second internal passage.
 22. The method of claim 21, wherein thesecond tubular member is part of a quill operably coupled to a topdrive, the third tubular member is a sleeve of the top drive, and thefourth tubular member is a piston of the top drive.
 23. The method ofclaim 18, wherein employing the bearing housing to rotatably support thefirst tubular member comprises disposing a radial bearing coupled to thefirst tubular member in the bearing housing, the radial bearingcomprising: a first ring to engage the first tubular member; and asecond ring engaged with the bearing housing, the second ring extendingcircumferentially about, and spaced along the first axis from, the firstring; wherein the first flat bearing and the second flat bearing aregenerally annular in shape and define an inside diameter; and whereinthe inside diameter of the first flat bearing and the second flatbearing is greater than or equals to a diameter of the second ring. 24.A method, comprising: spacing apart first and second tubular members;coupling a third tubular member to each of the first and second tubularmembers so that the third tubular member extends therebetween; rotatablysupporting each of the first and second tubular members; and reducingany bending moment experienced by the third tubular member whilerotatably supporting each of the first and second tubular members. 25.The method of claim 24, wherein the first, second, and third tubularmembers extend longitudinally along a first axis; wherein rotatablysupporting each of the first and second tubular members comprises:disposing a bearing housing in an opening defined by a first housing;and extending the first tubular member within the opening so that thebearing housing circumferentially extends around the first tubularmember; and wherein reducing any bending moment experienced by the thirdtubular member during rotatably supporting each of the first and secondtubular members comprises: permitting movement of the bearing housingwithin the first housing and along a second axis that is perpendicularto the first axis; and preventing movement of the bearing housing withinthe first housing and along the first axis.
 26. The method of claim 25,wherein the bearing housing moves in a first direction along the secondaxis; and wherein the method further comprises urging the bearinghousing to move in a second direction along the second axis in responseto the movement of the bearing housing in the first direction along thesecond axis, the second direction being opposite to the first direction.27. The method of claim 25, wherein the second tubular member is part ofa quill operably coupled to a top drive, and the third tubular member isone of a sleeve and a piston associated with the top drive.